Copper Sulfate – Saline Etch for Aluminum – Test 14: 5-Gallon Bath

Name: Nick Osetek & Tessa Chambers                                                 Date: 5/17/2018

Room Temperature: 70*F                                                                    Humidity etc: Dry

Experiment Title: 5-Gallon Bath Test

Experiment Goal: We made a new, bigger bath to etch larger plates, rather than our 3×3 inch plates. We’re hoping to get a more accurate representation of what will happen when etching larger plates. For this experiment we kept etching our 3×3 inch plates to test the strength of the new bath and so we could stay consistent with our other experiments. We will do another gradient step test with 6 plates.

Plate material: Aluminum (5052)

Plate Preparation: Steel wooled, degreased with Bon Ami and soy sauce, then backed with contact paper.

Evaluation of Plate Preparation: Normal

Etching Bath Notes: The bath has its brand new, bright blue color, but not as clear blue as we expected. We concluded that it may be from the ingredients for the bath not dissolving completely.

Time in bath15 sec, 1 min, 3 min, 5 min, 8 min, 12 min

After Bath Evaluation:  The bath was a tad darker due to the copper output during etching.

Removal of Grounds: N/A

Inking Methods: Bone black, 10% Burnt Plate Oil 00

Paper Type: Hahnemule Copperplate

Soaking Time: 30 min – 1 hour

Press, blanket set up, pressure: Praga press, 2 blankets, 1/8, 1/8

Conclusions: The results came out much darker compared to past tests due to how fresh the bath is. The 3 & 5-minute plates seem darker than our 8 & 12-minute plates. This brings up the question (since we’ve run into this problem before) does the aluminum reach a point of exhaustion when trying to etch black in large open areas? Is it the metal or the mordant?

5-gallon bath setup.

15-plate step test of new 5-gallon bath.

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